let str:any="666"

function foo(){
    return 123;
}
function bar(){
    return "123"
}
let flag:boolean=true;
let result:unknown;

if(flag){
    result=foo();
}else{
    result=bar();
}

//unknown 类型只能赋值给unknown和any类型
let res:unknown=result;
function baz(): never {
       while(true){}
}
let tulp:[string,number,boolean]=["1",2,true]//元组
export {}